Unexpected Formation of Polydentate Phosphinoalkyl−Silyl and −Germyl Ligands from Reaction of [MoH<sub>4</sub>(Ph<sub>2</sub>PCH<sub>2</sub>CH<sub>2</sub>PPh<sub>2</sub>)<sub>2</sub>] with Organosilanes and Organogermanes: Novel Activation of Mo−H, E−H (E = Si, Ge), and C−H Bonds in the Same System
作者:Makoto Minato、Da-Yang Zhou、Li-Bin Zhang、Ryo Hirabayashi、Masaki Kakeya、Takaomi Matsumoto、Akifumi Harakawa、Gosuke Kikutsuji、Takashi Ito
DOI:10.1021/om0401298
日期:2005.7.1
Reaction of [MoH4(Ph2PCH2CH2PPh2)(2)] (1) with PhEH3 (E = Si, Ge) in refluxing toluene yielded the novel complexes [MoH3[Ph2PCH2CH2P(Ph)C6H4-o](2)(Ph)E-PPPPE}] (E = Si (2), Ge (3)) with a quinquidentate ligand comprised of a P-P-E-P-P framework as a result of the oxidative addition involving E-H bond cleavage with concomitant selective activation of the ortho C-H bonds of the two dppe ligands. When secondary Ph2SiH2 was employed in a similar reaction with 1, a trihydrido complex with a tridentate ligand ([Ph2PCH2CH2P(Ph)C6H4-o]Ph2Si-P,P,Si) comprised of a P-P-Si framework was isolated. On the other hand, the reaction between Ph2GeH2 and 1 proceeded with accompanying evolution of I mol of benzene to give 3; that is, in addition to the Ge-H and C-H activation, Ge-C(Ph) bond cleavage took place. It is concluded that the reaction path includes the intermediacy of silylene or germylene metal complexes via an a-migration process on the basis of deuterium-labeling studies.